CN1315341C - Method and system for managing mobile unit to network connection - Google Patents

Abstract

The present invention relates to a method and a system thereof for managing a mobile unit to network connection. The mobile unit is provided with at least one kind of user plane connection used for transmitting user services from and/or to the mobile unit and at least one kind of control plane connection used for connecting the mobile unit with a radio access network signaling. When reposition connected with the mobile unit is executed, only the user plane connection is repositioned, and the control plane connection is constant. The connection is connected by an Iu interface, namely that the control plane is an Iu control plane which is wirelessly accessed to a control device, and the user plane is an Iu user plane which is wirelessly accessed to a control device.

Description

Method and system for managing mobile unit to network connection

technical field

The present invention relates to a method and system for managing the connection of a mobile unit to a network.

Background technique

In the current third-generation mobile network, the connection between the core network (CN) and the access network (AN, or radio access network, RAN) is realized through the Iu interface. At least that's what 3GPP UTRAN and GERAN RAN require. The Iu interface consists of two separate instances, the Iu-CS for connection to the circuit-switched core network domain, and the Iu-PS for connection to the packet-switched core network domain. Both interfaces consist of a Control Plane (CP) for signaling (defined by the RANAP signaling protocol and transport stack) and a User Plane (UP) for transporting user data—voice and data frames (defined by the Iu frame protocol and transport stack definition).

When a mobile station (MS) is connected to the RAN, it has a signaling connection that exists in the Iu CP (if the MS is connected to both the Iu-PS and the Iu-CS, there are two signaling connections in the Iu CP ). If the MS also has one or more active radio access bearers (RAB='calls'), it has one or more user plane connections in Iu UP.

In the current UTRAN architecture, the Radio Network Controller (RNC) terminates the Iu interface (UP and CP protocols).

When a mobile unit, such as MS or UE (User Equipment), moves in the RAN, the Iu connection used by the mobile unit may need to be relocated, that is, moved from one RNC to another RNC. This can happen, for example, if the cell used by the mobile unit is not under the direct control of the RNC connected to the core network terminating the Iu interface. As an example, the above relocation becomes necessary when the UE moves from a cell controlled by a first RNC to a cell controlled by a second RNC. This relocation is supported by a set of procedures in the RANAS protocol (RANAP, SRNC relocation) and exists when control plane and user plane connections move from a "source" or "serving" RNC to a "destination" RNC.

In IP-based RAN architectures such as the IP RAN architecture that will be used as GERAN and the new enhanced UTRAN, the user plane and control plane of the radio controller (RNC and BSc). This means that the Iu control plane is terminated in a network element (called RAN Access Controller or Server RNAS) and the Iu user plane is terminated in another network element (called RAN Gateway, RNGW) . Thus, such proofs are problematic, or at least wasteful, or suboptimal.

Contents of the invention

In summary, the present invention provides a method and system for relocating the user plane of a CN-RAN connection in a 3G network.

According to the present invention there is provided a method of managing the connection of a mobile unit to a network, said mobile unit having at least one user plane connection for transporting user traffic from and/or to the mobile unit, and for said mobile unit at least one control plane connection to a signaling connection of the radio access network,

wherein when performing relocation of a mobile unit connection, only said user plane connection is relocated and said control plane connection remains unchanged,

Wherein the user plane connection relocation procedure is initiated by the control unit of the network sending a message to the core network CN domain, the message including at least one new transport address to be used for the user plane traffic of the mobile unit.

According to another aspect of the present invention there is provided a system for managing the connection of a mobile unit to a network, said mobile unit being adapted to have a means for transmitting user traffic from and/or to the mobile unit when connected to the network at least one user plane connection, and at least one control plane connection for a signaling connection of the mobile unit to the radio access network,

wherein when relocation of the mobile unit connection is to be performed, the system only relocates the user plane connection and leaves the control plane connection unchanged,

Wherein said system comprises a control unit for initiating a user plane connection relocation procedure by sending a message to the core network CN domain, said message comprising at least one new transport address for user plane traffic of the mobile unit.

In particular, the method and/or system is adapted to manage the connection to the network of a mobile unit having at least one user plane connection for transporting user traffic from and/or to the mobile unit, and at least one connection for The mobile unit is connected to a control plane of a radio access network, preferably an IP-based access network, for signaling connections. When relocation of the mobile unit connection is to be performed, only the user plane connection is relocated, while the control plane connection remains unchanged. The connection is preferably an Iu interface connection, ie the control plane is the Iu control plane of the radio access control device and the user plane is the Iu user plane of a radio access control device.

The user plane and control plane can be connected to separate logical or even separate physical network elements.

In a distributed architecture, with different network elements terminating the Iu control plane and the Iu user plane, the invention provides the possibility to relocate only the user plane connections (e.g. when the cell used by the MS is inconveniently connected to the RNGW used ).

The advantages of explicitly relocating only the user plane are:

In order to occupy lower transmission resources, only the path of the user plane is optimized. Since the amount of data transferred on the user plane is an order of magnitude higher than the amount of data transferred on the control plane, there is no need to relocate the control plane.

Control plane relocation is a rigorous process, as the UE RR state will be frozen and transferred to the target RNC, and doing so must be consistent with Iu and RR (radio resource) signaling. Also advantageously avoids the extra non-deterministic signaling and Iu interface that would be required for control plane relocation.

If for some reason the RNGW is overloaded and can no longer handle all user plane traffic (this can be caused by a hardware failure, or in the case of a user plane connection using an MS requesting the RNGW that cannot be handled) , the user control plane can be converted without converting the control plane.

Thus the present invention discloses the general idea of switching the user plane connection but keeping the control plane connection unchanged. This concept is preferably implemented with respect to the Iu interface.

Relocating only the user plane enhances the flexibility and scalability of the IP-based distributed radio access network.

Description of drawings

Figure 1 illustrates an embodiment of a system according to the structure and function of the present invention;

Figure 2 illustrates an embodiment of the method and system according to the present invention.

Detailed ways

Figure 1 shows an embodiment of the invention comprising one or more mobile stations 1 connectable to a communication network comprising a control plane 2 and a separate user plane 3 . The term mobile station as used herein includes all types of mobile units such as portable computers, mobile telephones, portable user equipment, etc. having data and/or voice transmission/reception capabilities.

The control plane 2 includes a Radio Access Server (RAS) 4 for signaling control of the connection and connection of the MS1 to the network. The Radio Access Server (RAS) 4 thus terminates the Iu control plane. In addition, the control plane 2 includes a server (CRRM server) 5 for public radio resource management.

The user plane 3 includes one or more base stations 6, a RAN (radio access network) gateway (GW) 7 for connection of Iu to a circuit switched (CS) network (not shown), and also a RAN GW 8 for connection to a packet switched ( PS) connection to a network (not shown). RANGW8 provides Iu connectivity to Packet Switched (PS) networks.

Fig. 2 schematically shows the process flow and structure of executing the relocation process, only the user plane connection (IU user communication service connection) is relocated but the control plane connection remains unchanged.

As shown in FIG. 2, when the mobile station 1, which may include user equipment (UE), is required to be relocated, for example because of the movement of MS1, the radio network controller RNC11 (possibly a base station controller BSC or similar), sends a message to the core network (CN) 12 Send a message including a new transport address for user plane traffic between MS1 and the network. CN12 registers a new transport address for user plane traffic of MS1 and then uses this new transport address for user traffic to MS1.

CN12 will return a response message to RNC11, informing them that they have received a new transmission address (reception response).

As shown in Figure 2, in order to keep the connection to the control plane the same as before, the Iu connection of the signaling connection between MS1 and RAS4 remains unchanged.

The present invention provides several optional solutions for only relocating the Iu user plane while keeping the terminal of the Iu control plane unchanged.

One solution is to modify the current RANAP protocol to this effect. This solution provides the possibility for the RAN terminating the Iu user plane interface to determine the change of the transport address.

An existing protocol can be modified in several possible ways (the first is preferred):

The first method shown in Fig. 2, as described above, consists in providing a new process (called "internal RNS relocation", for example). This procedure is started eg by the RNC11 sending a message to the corresponding CN12 domain including the new transport address for the user plane procedure of the specific mobile station 1 . This process is completed through the response message sent by CN12 to RNC11 (other messages may also be provided).

As a second approach, the current basic set of processes defining RNS relocation as defined in the 3GPP specifications can be modified in order to include "internal RNS relocation" as a special case. This means that the "target RNCID" is not specified in the message required for SRNS relocation, which includes information that does not change the control plane address. Then carry out the process as normal. In this way, the SRNS relocation required message sent during the RNS relocation process includes information indicating that the control plane address is not to be changed. This information in the message will for example consist of one of the following options: The message does not include a field with a target ID. Alternatively, the information may be a field indicating that destination ID=source ID. This information may also be an explicit parameter indicating "no control plane changes".

Further, the process needed to reconfigure the RAB can be used. This process may indicate that the QoS characteristics of the existing RAB need to be reconfigured from the RNS to the CN. This procedure can be used to indicate that IP addresses only need to be changed in the DL (downlink) direction. Then the CN will run the RAB assignment process, and only change the IP address of DL (maybe GTP TEID) again, and switch the DL connection of U-Plane, while the C-Plane connection is maintained.

When these changes are done, the result is that only the user plane is relocated, which improves the flexibility and upgradeability of the IP-based distributed radio access network.

The invention provides a radio access network with the possibility to stabilize the control plane connection to the CN while only relocating the user plane. This is possible because of the mutual independence between the user plane and the control plane of the Iu interface.

Iu user plane relocation is an advantageous feature in IP RAN products.

The user plane for relocating CN-RAN connections can be provided for 3G networks, but also in various other types of networks, eg, IM, GPRS and UMTS domains.

Although the invention has been described above with reference to specific embodiments, the scope of protection of the invention extends to include all improvements, deletions, additions and corrections of the disclosed nature.

Claims (18)

1, a kind of managing mobile unit is to the method for the connection of network, described mobile unit have be used to transmit from and/or connect at least one user plane of the customer service of mobile unit, and be used for described mobile unit and connect at least one control plane that the signaling of Radio Access Network connects

Wherein when carrying out the reorientation that mobile unit connects, only the described user plane of reorientation connects, and described control plane connects and remain unchanged,

Wherein the control unit by described network starts user plane connection reorientation process to core network CN territory transmission message, and described message comprises at least one new transport address of the user-plane traffic that is used to described mobile unit.

2, according to the process of claim 1 wherein that described connection is that the Iu interface connects.

3, according to the method for claim 1 or 2, wherein said control plane is the Iu control plane of wireless access control apparatus, and described user plane is the Iu user plane of described wireless access control apparatus.

4, according to the method for claim 1 or 2, wherein said user plane and control plane are connected to logical block separately.

5, according to the process of claim 1 wherein that described user plane and control plane are connected to physical network element separately.

6, according to the process of claim 1 wherein that described Radio Access Network is based on the access network of IP.

7, according to the process of claim 1 wherein that described user plane connects the reorientation process and finishes by the response message from described core network to described control unit.

8, describedly be used to start message that user plane connects the reorientation process and comprise and be used to indicate the information that should not change described control plane address according to the process of claim 1 wherein.

9, according to the method for claim 1, wherein be used for the process that RAB reconfigures, wherein need reconfigure the QoS characteristic of existing RAB RAB to described core network indication, wherein said process indication needs to change the IP address of down link direction, follow described core network and carry out the RAB distribution process, only change down link IP address, in order to the down link connection on converting users plane, and the connection of described control plane is held.

10, according to the process of claim 1 wherein that described process also changes the GPRS tunnel end identifier GTP TEID of described down link.

11, a kind of managing mobile unit is to the system of the connection of network, described mobile unit is used for when being connected to network, have be used to transmit from and/or connect at least one user plane of the customer service of mobile unit, and be used for mobile unit and connect at least one control plane that the signaling of Radio Access Network connects

Wherein in the time will carrying out the reorientation of described mobile unit connection, described system only reorientation user plane connects, and the connection of retentive control plane is constant,

Wherein said system comprises control unit, is used for starting user plane connection reorientation process by send message to core network CN territory, and described message comprises at least one new transport address of the user-plane traffic that is used for mobile unit.

12, according to the system of claim 11, wherein said connection is that the Iu interface connects.

13, according to the system of claim 11 or 12, wherein said control plane is the Iu control plane of wireless access control apparatus, and described user plane is the Iu user plane of described wireless access control apparatus.

14, according to the system of claim 11, wherein said user plane and control plane are connected to logical block separately.

15, according to the system of claim 11, wherein said user plane and control plane are connected to physical network element separately.

16, according to the system of claim 11, wherein said Radio Access Network is based on the access network of IP.

17,, wherein utilize response message to finish described process from described core network to described control unit according to the system of claim 11.

18,, wherein saidly be used to start message that user plane connects the reorientation process and comprise and be used to indicate the information that should not change described control plane address according to the system of claim 11.

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